Hygroscopic materials have been used in terrains to regulate moisture. In agricultural, turf maintenance and other applications, hygroscopic materials have been introduced to absorb rain and irrigation water. The absorbed water is released by the materials over an extended period of time.
Tilling equipments are generally used to plow soil to deliver the materials sub-surface. However, tilling causes soil erosion, destroys turf, and sub-surface disturbances damage in-ground irrigation. In golf greens and other areas, tilling prevents use of the land for a significant amount of time.
High pressure jets, often utilizing venturi effects, have been used to deliver the materials into the soil. While such high pressure jets allow delivery of the materials into the sub-surface without tilling, existing high pressure jets do not precisely control the amount of materials delivered.